Speed Plastics specialises in high frequency welding of flexible plastics and also offers customers bespoke engineering solutions in sectors such as healthcare, aviation, defence and marine. Adhesive and dispensing specialist Techsil was approached to find a transparent flexible adhesive to bond the mouthpiece of a smoke hood and plan a new method of production.
A number of adhesives had been tried, but under stress tests were found to be too brittle for the substrates, which were silicone rubber and cotton-backed PVC. Furthermore, the contours of the mouthpiece made applying the adhesive by hand very tricky. A 1-part flowable silicone adhesive was recommended by Steve Green, one of Techsil’s application development engineers.
“Momentive IS5628E silicone adhesive cures at room temperature, requires no mixing and its flowable consistency makes it easy to apply,” says Green. “It adheres well to silicone rubbers and cures to make a tough durable bond, which can withstand very high and low temperatures; making it an ideal solution for this application.”
For the production process, a semi-automated system was chosen. A circular, even bead of adhesive was required, and a Nordson EFD Ultimus 1 dispenser with a 310 cartridge assembly was deployed and a fly press to deliver the adhesive. The hood and mouthpiece are placed on a turntable and rotated 360 degrees during dispense.
Overall, this project has increased the speed of the manufacturing process. The Momentive IS5628E adhesive produces a sound bond that is uniform and repeatable, due to the automated dispensing. In addition, adhesive wastage has been eliminated, which was an inevitable outcome of hand application.
LOW ODOUR, HIGH APPEAL
Meanwhile, Techsil has introduced a new two-component high-performance structural adhesive from Panacol. Penloc GTN is described as an easy-to-process, methyl acrylate-based, low-odour adhesive that can be used in a wide variety of applications.
Penloc GTN adheres especially well to brass, ceramics, steel, aluminium, PVC and similar materials, said Techsil. “The performance adhesive boasts a high-power transmission capability and excellent thermal stability. It is both flexible and offers superior adhesion. Compared to other methyl acrylate adhesives, it has the advantages of a low-odour formation and a long processing time of ten to 15 minutes.”
To allow effective monitoring of blending quality, the two components of Penloc GTN have different colours that, applied thinly, change to a grey, almost colourless, surface as the blend cures. Penloc GTN can be dispensed from a handy 50 ml double cartridge or from drums connected to dispensing.
